The detection of Type 1 retinopathy of prematurity (ROP) usually relies on repeated eye exams. A potentially more efficient strategy would be to use telemedicine, with remotely evaluated retinal digital images. Although this approach has been adopted by some neonatal intensive care units (NICUs), little is known about the relative comparative effectiveness. The objective is to compare expected outcomes from different Type 1 ROP detection approaches.

Methods

We used a microsimulation model with weekly cycles to simulate ROP status and detection strategy outcomes. We simulated a cohort of 650 infants, the typical number of annual admissions to NICUs affiliated with children's hospitals, using probabilities taken from the e-ROP study (n=1,257 from Level III NICUs). We assumed that evaluation for ROP would begin at post-menstrual age (PMA) 32 weeks for those with GA < 30 weeks and at 34 weeks for GA of 30 weeks. Exams were considered to be the gold standard and that evaluation would stop at the time of discharge or after 40 weeks PMA, or upon the diagnosis of Type 1 ROP or mature retinae. Telemedicine findings suggestive of Type 2 or Type 1 ROP would lead to an exam. Telemedicine cannot identify mature retinae because of imaging limitations.

Results

The table summarizes the expected number of exams, digital imaging sessions, Type 1 ROP cases, and the number that need follow-up after discharge among the cohort of 650 infants from three strategies: usual care (biweekly exams after immature retinae but otherwise weekly), telemedicine alone, and telemedicine with an exam at discharge. The number of exams and screens required for each scenario varied significantly by GA because those with greater GA had a lower overall risk of Type 1 ROP and would be discharged earlier. For example, usual care among those with GA≤25 weeks requires an average of 5.4 exams/infant and telemedicine requires 2.6 exams/infant and 4.9 screens/infant compared to, among those with GA=30 weeks, 1.4 exam/infant for usual care and 0.5 exams and 1.5 screens/infant for telemedicine. All results were robust to sensitivity analyses.

Conclusions

The optimal strategy for ROP detection depends upon access to eye care services, the NICU case- mix, and the ability to follow-up infants after discharge.